Fluorinated carbon compounds are finding increasing utility in modern industry, such as the electronics fabrication industry, and researchers have found heightened interest in fluorinated compounds for various biological and medical applications, such as synthetic blood and diagnostic fluids.
Perfluorinated multiple condensed ring compounds have been known for a significant period of time, such as perfluorophenanthrene as disclosed in U.S. Pat. No. 2,487,820. That patent makes a broad, general and unsupported disclosure that:
"Fused-ring aromatic hydrocarbons such as anthracene, naphthalene, phenanthrene and their substitution derivatives, can be fluorinated readily with the addition of fluorine atoms at the points of unsaturation and, if desired, with the replacement of hydrogen in the molecule, and the production of saturated fluorine-containing compounds."
Partially fluorinated compounds are exemplified by the 1-methyl-(3,3,3-trifluoropropyl) naphthalene compounds disclosed in U.S. Pat. No. 4,396,785. These compounds are only marginally fluorinated and the condensed carbon rings retain their unsaturated aromatic character.
The tertiary butyl derivatives of a single carbon ring, cyclohexane, is disclosed in U.S. Pat. No. 4,453,028.
Perfluoro-2-methyldecahydronaphthalene has been reported to have been synthesized from 2-methyl naphthalene using cobalt trifluoride fluorination technology as set forth in article titled, Organic Fluorides. Part V. Fluorination of Hydrocarbons With Cobalt Trifluoride by R. N. Haszeldine and F. Smith appearing in Journal of Chemistry Society (1950) pages 3617 to 3623.
The cobalt trifluoride fluorination of 1-methyl decalin to produce perfluoro-1-methyl decalin has also been set forth in British Patent No. 1,281,822. Fluorination of substituted naphthalenes is generally disclosed.
The basic technique for cobalt trifluoride fluorination is set forth in U.S. Pat. No. 2,631,170.
U.S. Pat. No. 3,775,489 is directed to the fluorination of various aromatic carbon compounds of the naphthalene and anthracene class.
U.S. Pat. No. 3,786,324 discloses a utility for perfluorinated hydrocarbons comprising dielectric fluids for capacitors. The compound 1-trifluoromethyl perfluorodecalin is mentioned as a potential dielectric fluid.
U.S. Pat. No. 4,106,557 describes a refrigeration apparatus utilizing various halogenated carbon refrigerants, including cyclic fluorinated carbon ethers.
U.S. Pat. No. 4,143,079 discloses perfluorinated 1-methyl-4-isopropyl cyclohexane. This material is recited to have utility as an artificial blood component.
U.S. Pat. No. Re. 30,399 discloses a technique for soldering electronic components in a mass production mode in the heated vapor of a boiling fluid wherein the vapor condenses on cold solder to be reflowed and the solder is melted by the heat of vaporization evolved during the condensation of the adhering fluid vapor. This form of soldering is known as vapor phase soldering, condensation soldering and various reflow soldering nomenclatures. The criteria delineated for a heat transfer liquid for such soldering includes: a boiling point above the melting point of the solder wherein the boiling point is preferably sharply defined and dependent upon a single component rather than multicomponent materials, electrically non-conducting characteristics, vapors which are non-oxidizing, chemically stable and inert, non-toxic, non-inflammable and relatively denser than air, relatively high latent heat of vaporization, and degreasing properties. Fluorinated polyoxypropylene is a disclosed fluorocarbon suitable for heat transfer liquid choice.
U.S. Pat. No. 4,549,686 describes vapor phase soldering using perfluorotetradecahydrophenanthrene (perfluorophenanthrene).
British Patent No. 785,641 discloses the fluorination of various carbon compounds with hydrogen fluoride wherein such compounds include benzene, toluene, anthracene and diamylnaphthalene. Retene, which is 1-methyl-7-isopropyl phenanthrene, is also capable of the recited fluorination treatment.
U.K. Patent Application No. 2110204A discloses various perfluoroalkyl cyclohexane mixtures useful for vapor phase soldering in the boiling range of 180.degree. to 300.degree. C. These materials are produced by the fluorination of narrow cut linear alkylbenzene compounds with cobalt trifluoride.
European Patent Application No. 0 194 009 discloses fluorochemical compositions comprising compounds in the form of perfluoropolycycloalkane ring assemblies having (a) at least two perfluorinated cyclohexane rings, (b) at least two perfluorinated fused ring systems, or (c) a combination of at least one perfluorinated fused ring system with at least one perfluorinated cyclohexane ring, each perfluorinated ring or ring system being directly joined to another perfluorinated ring or fused ring system by a single bond. The rings may have certain substituent groups.
The prior art fluorination compounds have failed to provide a stable inert perfluoro compound having a desirable sharp boiling point in the approximate range of 215.degree. C. which is most desirable for presently existing vapor phase soldering utilities. In addition, the prior art compounds suffer from various levels of susceptibility to heat degradation to hydrogen fluoride and perfluoroisobutylene, as well as having undesirable fluorine utilizations due to significant levels of aliphatic character. The present invention overcomes these shortcomings.